1) The MIT_App_Inventor_Tools_2.3.0_win_setup.exe is the correct aiStarter to use with the online MIT App Inventor 2 web application. That is the only version of aiStarter you should install Fernando.
3) Regarding your issue with WIFI, are you using a home network or a school or perhaps library network? Some firewalls within schools and organizations do not allow the type of WiFi connection required.
Did anything here help?